Nathan Dunlap killed four people at a Chuck E. Cheese in 1993 (HANDOUT | )

Death stepped closer to Nathan Dunlap on Tuesday, when the U.S. Supreme Court rejected the best legal chance the convicted murderer had left to avoid execution.

Dunlap was sentenced to die for killing four people in 1993 at an Aurora Chuck E. Cheese restaurant.

In a list of unsigned orders issued Tuesday, the nation's highest court said it would not hear the last appeal Dunlap is legally guaranteed, bringing an end to a more than decade-long appellate process and clearing the way for an execution date to be set. Dunlap, 38, may file further appeals, but they are not certain to delay his execution by lethal injection.

Dunlap is Colorado's longest-serving death-row inmate. He has spent more time behind bars — roughly half his life — than some of his victims spent alive.

"We're one step closer," said Jim Peters, the former Arapahoe County District Attorney who was the prosecutor in Dunlap's murder trial. "It's not finalized. But we've taken another major step forward."

Dunlap's attorneys said they were disappointed by the decision. They declined to comment on whether they would attempt additional appeals. They are also working on a petition for clemency to send to Gov. John Hickenlooper.

"Mr. Dunlap should spend the rest of his life in prison without the possibility of parole," said Phil Cherner, one of two attorneys representing Dunlap in his appeal. "What happened is tragic. But taking his life isn't going to change that."

What happens next is uncertain. It has been more than 15 years since Colorado last executed an inmate — killer Gary Lee Davis, in 1997.

Dunlap's lawyers and a spokesman for the state Judicial Branch said the next step is for prosecutors from Arapahoe County — who handled the murder case — to ask the trial court to issue a death warrant. But a spokeswoman for the Arapahoe County District Attorney's Office said lawyers there are still studying what their next move must be.

Nathan Dunlap in court in 1996 (|file)

"One of the things we're wrestling with is the lack of precedent," Cherner said. "What happens from here?"

In an e-mailed statement, Arapahoe County District Attorney George Brauchler said he remains committed to seeking execution for Dunlap.

"I will continue to seek imposition of the death sentence in this case, in the interests of justice," Brauchler said. "Our office has spent nineteen years prosecuting Nathan Dunlap for the preplanned and deliberate murders of the unsuspecting three teenagers and one adult victim who had the terrible misfortune to be working the night shift on December 14, 1993 at Chuck E. Cheese in Aurora."

On that night, Dunlap waited in the bathroom until after the restaurant closed, then shot Sylvia Crowell, 19, and Ben Grant and Colleen O'Connor, both 17. He wounded another young employee before killing a restaurant manager, 50-year-old Margaret Kohlberg.

He escaped with about $1,500 in cash and some restaurant key chains and game tokens. He was arrested the next day. Police said Dunlap was upset after being fired from his job at the restaurant.

Dec. 23, 1994: Dunlap offers to plead guilty in exchange for life in prison without parole. The district attorney rejects the offer, saying Dunlap deserves death.

Nov. 3, 1995: Dunlap is convicted of robbing an Aurora Burger King about a month before the Chuck E. Cheese shootings. The robbery conviction will be used to win a death sentence against Dunlap for the shootings.

Feb. 26, 1996: Dunlap is convicted of eight counts of first-degree murder, two counts for each victim.

March 7, 1996: The same jury sentences Dunlap to death.

March 8, 1999: State Supreme Court upholds Dunlap's death sentence.

Sept. 10, 2001: State Supreme Court rejects an appeal to reduce Dunlap's death sentence to life in prison.

Boulder is pretty good at producing rock bands, and by "rock," we mean the in-your-face, guitar-heavy, leather-clad variety — you know, the good kind. For a prime example, look no farther than BANDITS. Full Story